Pathophysiology of Cardiovascular Disorders

Question 1

Define the overall definition
of CV disease and the possible causes

Answer 1

insufficient blood supply to the body caused by heart, vessels or blood volume issues

Question 2

What are the mechanisms involved with CV diseases?

Answer 2

blockage, congestion, distribution

Question 3

Define atherosclerosis

Answer 3

thickening/hardening of the arteries with build up of plaque in inner lining of artery causing narrowing and reduction of lumen of blood vessels -> reduced blood flow

Question 4

Describe the 3 stages of atherosclerosis

Answer 4

1) endothelial injury: naturally occurring wear and tear, caused by physical forces eg flow disturbance/shear stress or chemical irritants eg tobacco
2) lipid penetration: endothelial injury results in defective barrier allowing circulating lipoproteins to enter arterial wall, these accumulate in sub-endothelial space and bind to proteoglycans, low density lipoprotein oxidation occurs
3) foam cells and plaque formation: monocytes infiltrate blood vessels and differentiate into macrophages which endocytose modified lipoproteins resulting in foam cells, insufficient clearance of dead foam cells, accumulation of cellular debris and extracellular lipids = atherosclerotic plaque

Question 5

What can atherosclerosis lead to?

Answer 5

arterial stenosis, degeneration of arterial walls, ischemia in each organ/limbs, stroke, myocardial infarction

Question 6

Describe CHD

Answer 6

atherosclerotic plaque build-up in coronary arteries, vessel stenosis gradually occurs -> ischemia/infarction of heart tissue, heart function negatively impacted

Question 7

compare atherosclerosis in coronary artery in cases of myocardial infarction and angina

Answer 7

myocardial infarction: occlusion of coronary artery
angina: stenosis of coronary artery with chest pain

Question 8

Compare STEMI and NSTEMI

Answer 8

STEMI: elevated ST segment caused by blockage
NSTEMI: non-elevated ST segment (depression) caused by partial blockage

Question 9

Compare clinical presentation stable vs unstable angina

Answer 9

stable: chest pain on exertion
unstable: chest pain at rest

Question 10

describe clinical presentation of myocardial infarction

Answer 10

severe crushing pain at rest radiating from centre of chest to arms and neck, impending sense of doom, sweating, tachycardia, SOB, nausea, vomiting, palpations, light headedness, weakness, fatigue

Question 11

Describe peripheral vascular disease

Answer 11

atherosclerotic plaque build up in main arteries supplying lower limbs resulting in stenosis, occlusion, downstream ischemia

Question 12

describe the clinical presentation of acute limb ischemia

Answer 12

6P’s: pallor, pain, pulselessness, paralysis, paraesthesia, perishingly cold

Question 13

describe the clinical presentation of chronic limb ischemia

Answer 13

dry skin, decreased hair growth, ulceration, decreased pulses, intermittent claudication

Question 14

describe symptoms of critical limb ischemia

Answer 14

pain, ulceration, gangrene

Question 15

define HF

Answer 15

inability for heart to supply sufficient oxygen, nutrient rich blood to meet metabolic demands of body

Question 16

list the different types of HF

Answer 16

HF with reserved EF (>50%)
Mid-range EF (40-50%)
Reduced EF (<40%)
Right ventricular systolic dysfunction

Question 17

What are the 3 key factors to be considered in HF?

Answer 17

preload, afterload and inotropy

Question 18

Define preload and possible complications involved

Answer 18

preload is the stretch of the ventricles associated with the filling of the chambers
complications include insufficient or excess filling results in ineffective ventricular ejection

Question 19

Define afterload and possible complications involved

Answer 19

afterload is the force/pressure the ventricle has to overcome to open the valves
complications include increased afterload due to HTN, atherosclerosis, valve stenosis causing hypertrophy which can be eccentric = increased heart length caused by volume overload or concentric = increased heart width caused by increased afterload

Question 20

define inotropy and list factors affecting it

Answer 20

inotropy is the measure of contractile strength of the cardiomyocytes
ineffective inotropy is primarily caused by myocardial infarction but also can be caused by infiltration of calcium, fibrin, amyloid, tumours

Question 21

List the main causes of HF

Answer 21

impaired contractility, significant increase in afterload, chronic pressure overload, impaired diastolic filling

Question 22

List some characteristics of HF

Answer 22

decreased SV, cardiac output, BP, contractility, increased HR

Question 23

List the symptoms of HF due to their causes and determine whether these are a backward or forward effect

Answer 23

Congestion: difficulties breathing, oedema- backward effect
low output: fatigue, syncope, MOF- forward effect

Question 24

Describe aortic stenosis

Answer 24

aortic valve narrowing

Question 25

What causes aortic stenosis?

Answer 25

atherosclerosis, stiff bicuspid aortic valve

Question 26

Describe the symptoms of aortic stenosis

Answer 26

chest pain, syncope, SOB